Currently, there are many pressurized pumps of diaphragm type exclusively used in the reverse osmosis purification as disclosed in the U.S. Pat. Nos. 4,396,357, 4,610,605, 5,476,367, 5,571,000, 5,615,597, 5,626,464, 5,649,812, 5,706,715, 5,791,882, 5,816,133, 6,048,183, 6,089,838, 6,299,414, 6,604,909, 6,840,745 and 6,892,624; Their structure is as shown in the FIG. 1 through FIG. 3, which comprising: a motor 10; an upper hood chassis 11 at the end of the output shaft (not shown in the figure) of said motor 10, and having some screw bores 12 on the circumference of said upper hood chassis 11; some wobble plates 13 driven by the output shaft of said motor 10 to converted into axial reciprocating motion in said upper hood chassis 11; a diaphragm sheet 20 covering on said upper hood chassis 11; some piston head pushing chunks 30 disposed on said diaphragm sheet 20; a piston valve body 40 inset in said diaphragm sheet 20 and a pump cover body 50; By means of bolts 2 running through those said screw bores 12 on said upper hood chassis 11 and corresponding perforated holes 51 on said pump cover body 50, all components said above are assembled into a integral whole body (as shown in the FIG. 2).
Wherein, a ring of seal groove raised bar 21 is built on the top of the circumference at said diaphragm sheet 20, and some raised ribs 22 are radial built from its top center to joint with said seal groove raised bar 21, so that some piston acting regions 23 are partitioned by said raised ribs 22 and seal groove raised bar 21; And, a central perforated hole 24 is punched on each said piston acting regions 23 in alignment with the threaded hole 14 of each said wobble plate 13; By mean of each fixing screw 3 running through the internal ladder hole 31 on each said piston head pushing chunk 30 and each said corresponding central perforated hole 24 on each said piston acting region 23, said diaphragm sheet 20 and those said piston head pushing chunks 30 can be screwed on those said threaded holes 14 on said wobble plates 13 (as shown in the FIG. 2);
Moreover, a hemispherical concaved water drain base 41 facing said pump cover body 50 is built in the center of said piston valve body 40 with a positioning hole 42 in its center; a partition indented groove 43 is formed on each 120° included angle along the radial line from its center so that three isolated sectors are separated by these said indented grooves 43; some water drain ports 44 are created on each said isolated sectors, and some water inlet ports 45 are created on the circumference in correspondence with each said water drain port 44; an upside down flare piston sheet 46 is punched in the center of each said water inlet ports 45 so that enable each said flare piston sheet 46 to block each said water inlet ports 45; Said anti-reverse baffle plastics pad 47, which being a soft elastic hollow hemisphere of unitary body with a positioning pole 48 protruding in the bottom center, stays closely against the top surface tightly of said water drain base 41 on said piston valve body 40; a partition rib plate 49 is formed on each 120° included angle along the radial line from its center so that three isolated sectors are separated by these said rib plates 49; a protruding peg 481 is also formed on the outer peripheral surface in correspondence with each said rib plate 49; By means of plugging said positioning pole 48 into said positioning hole 42 on said water drain base 41 together with insetting each said protruding peg 481 into each corresponding said indented groove 43, the outer hemisphere surface of said anti-reverse baffle plastics pad 47 will tightly contact against closely all said water drain ports 44 on each sector of said water drain base 41 (as shown in the FIG. 2); Wherein, a water inlet chamber 100 is formed among said anti-reverse baffle plastics pad 47, all said water drain ports 44 on each sector of said water drain base 41 and said piston head pushing chunk 30 on said diaphragm sheet 20 (as shown in the FIG. 3); besides, one end of each said water inlet chamber 100 is connected with each said water inlet port 45.
Furthermore, some perforated holes 51 and a water inlet orifice 52 as well as a water outlet orifice 53 are created on the outer surface of said pump cover body 50 (as shown in the FIG. 1 and FIG. 3), which also having a ladder groove 54 and an annular groove 55 built inside; said ladder groove 54 is created at the bottom peripheral of said pump cover body 50 so that to closely contact with the outer peripheral of the assembly of said diaphragm sheet 20 and said piston valve body 40; said annular groove 55 is created in the internal center with bottom tightly press on the outer peripheral surface of said water drain base 41 on said piston valve body 40 so that a high pressure water chamber 200 is surrounded by space between the internal wall of said annular groove 55 and said water drain base 41 of said piston valve body 40 (as shown in the Fig.3).
Please refer to FIG. 4 and FIG. 5, the illustration shown is the operation way of conventional pressurized pumps of diaphragm type mentioned above. When tap-water flows into the water inlet orifice 52 on the pump cover body 50, the tap-water will push the flare piston sheet 46 on the piston valve body 40 open and flows into the water inlet chamber 100 via the water inlet port 45 on the piston valve body 40 (as shown by the arrow head in the FIG. 4); Upon all the wobble plates 13 being orderly driven by the output shaft of the motor 10, the piston head pushing chunk 30 on each said wobble plates 13 will be meanwhile brought to axial reciprocating motion, so that each piston acting region 23 on the diaphragm sheet 20 will simultaneously vibrate in displacement to squeeze the water in the water inlet chamber 100 to let water pressure increase up to 80 psi-100 psi; The high pressure water Wp will push the anti-reverse baffle plastics pad 47 on the water drain base 41 open and constantly flow into the high pressure water chamber 200 via each said water drain port 44 on said water drain base 41, then drain out of the pressurized pump via each water outlet orifice 53 on the pump cover body 50 (as shown by the arrow head of the FIG. 5) in order to provide the water pressure necessary for reverse osmosis by the RO membrane cartridge RO in the RO filter apparatus.
However, there is a common serious drawback in all the disclosed conventional pressurized pump of diaphragm type aforesaid as shown in the figures of 6 through 9. During the process of increasing water pressure after the start of the motor 10, each wobble plate 13 is tightly contacting with the diaphragm sheet 20 closely; hence, said diaphragm sheet 20 between said piston acting region 23 and wobble plate 13 will be pulled to stretch once when each time said wobble plate 13 moves in reciprocating motion to drive said piston acting region 23 on said diaphragm sheet 20 (as shown by the hypothetical line in the FIG. 8); thereby, said diaphragm sheet 20 will be pulled to stretch for 700 times in one minute if rotational speed is 700 rpm; thus, said diaphragm sheet 20 will loosely contact with said piston head pushing chunk 30 without hermetical seal due to long time and high frequent stretch (as shown in the FIG. 9); Consequently, the high pressure water Wp will leak and seep along the gap between the fixing screw 3 and the threaded hole 14 on each said wobble plate 13 and result in total disable and damage of the whole pressurized pump of diaphragm type in consequence of electric short circuit of said motor 10; Under the circumstance of such drawback having no effective solution so far in the manufacturing industry, the consumer has no choice in betting his own luck to buy a target pressurized pump with uncertain service lifetime; If he is unlucky to have motor 10 burnt out due to leakage, the result on fire is un-neglectful.
Moreover, except the aforesaid vital drawback, the other problematical position often leaking is between the piston valve body 40 and the pump cover body 50 as shown in the FIG. 10. When the piston acting region 23 on the diaphragm sheet 20 is constantly pushed and squeezed by the wobble plate 13, the top outer peripheral surface of the piston valve body 40 will constantly strike against and pull off the wall of the ladder groove 54 on the pump cover body 50 (as shown by the black arrow head in the FIG. 10); owing to both of said piston valve body 40 and pump cover body 50 being rigid body without any buffer structure contrivance, the gap will be easily created in between of which after long time of repeatedly strike against and pull off each other; Under high pressure action of water, the water will leak and seep out of the pressurized pump of diaphragm type via the gap between the wall of said ladder groove 54 on said pump cover body 50 and the top outer peripheral surface of said piston valve body 40; Thus, the total effect of increasing water pressure is reduced due to loss in this partial pressure.